Actually, as I think about it, Holdo was just an unnecessary character. It could have ben Ackbar (though it would have lowered my opinion of him). It's one think if they wanted to kill some random character and keep Ackbar alive, but he dies too? Nah, whatever.
The reason I am critical of Holdo is her need to keep her entire crew believing they were going to die and not telling them thatt her was a plan and a safe haven nearby. If a rational person has this conversation it goes like (paraphrased from memory):
Poe: "We have to do something! The First Order will finish us off."
Holdo: "Don't worry, we have a base on a planet nearby that we can get to while styaing just out of their range."
Poe: "Really? Great! But, maybe as a backup, we send Finn and Rose to see if they can sabotage that flagship."
Holdo: "Okay, let them give it a shot."
But instead, Holdo is all "Follow my orders. Don't question me!" It's like, really, and who are you exactly? Maybe if it were Leia, they would have just trusted her enough by reputation, but Holdo? Nah, the mutineers were right.